Mechanical key lock-in

ABSTRACT

A mechanical lock-in for a depressed key of a keyboard including an automatic release of the locked depressed key through successive actuation of associated key members.

United States Patent Long July 18, 1972 [5 MECHANICAL KEY LOCK-IN [56]1161mm; Cited [72] Inventor: Eric L. Long, Waukegan, Ill. Um STATESPATENTS 2,650,027 8/1953 Avery ..235/145 R [73] Ass'gnee' 2?? Cmpmum"3,024,988 3/1962 Wagemann ..23s/26 g 3,356,296 12/1967 Wirth ..235/27221 Filed: June 18, 1971 3,446,433 5/1969 Tibbetts ..235/27 [21] APPINO:154359 Primary Examiner-Stephen J. Tomsky Attorney-Edward C. Threedy 5210.8. CI. ..235/145 11, 235/26 51 1111. c1 ..G06c 7/04 ABSTRACT 53 Field61 Search ..235/26, 27, 145, 607 9173/2517; A mechanical 10cm" for adepressed key of a keyboard cluding an automatic release of the lockeddepressed key through successive actuation of associated key members.

6Clnims,7DrawingF1gures MECHANICAL KEY LOCK-IN SUMMARY OF THE INVENTIONA lock-in structure for a key of a keyboard for retaining a selected keyin a depressed condition, comprising a self-biased locking leverpivotally urged into an aperture formed in the stem of the key to belocked, with the locking lever pivoted out of the aperture by thedepression of an associated key member which is provided with a camsurface and connecting means for pivoting the locking lever in onedirection out of its operative position with respect to the depressedlocked key.

GENERAL DESCRIPTION The invention will be best understood by referenceto the enclosed drawings which illustrate the preferred embodiment ofthe invention, and in which:

FIG. 1 is a fragmentary top plan view of the keyboard showing theplacement of the keys and associated locking structure of thisinvention;

FIG. 2 is a fragmentary top plan view of two associated keys and thelocking mechanism of this invention in its normal or unactuatedcondition;

FIG. 3 is a fragmentary top plan view similar to FIG. 2, but showing thelocking lever in its actuated or locking position;

FIG. 4 is a top plan view similar to FIGS. 2 and 3 but showing thelocking lever in its released position;

FIG. 5 is a perspective view of the associated switch structures andlocking mechanism in an exploded relation with respect to each other;

FIG. 6 is a side elevational view of the locking lever of thisinvention;

FIG. 7 is a fragmentary detailed sectional view showing the pivotalmounting of the locking lever to one of the key structures.

In the present embodiment of the invention as illustrated, the keyboard10 accommodates a plurality of electrical switch keys. However, itshould be understood that the physical structure of the lock-in meanshereinafter to be described, can be utilized in a non-electricalkeyboard.

As fragmentarily shown, the keyboard 10 is provided with an arrangementof spaced openings 1 1 that are of a size to frictionally receive thebody enclosures 12 of the electric switch keys, two of which are shownat 13 and 14. Each of the body enclosures 12 of the switch keys providesa top edge peripheral flange 15 which rests upon the keyboard surface 161 surrounding each of the openings 1 1.

The switch keys 13 and 14 in addition to their body enclosures 12 eachprovide a stem 17 and 18 movable through a suitable opening 19 formed inthe top wall 20 of each body enclosure 12. It is to be noted that thefree ends of the stems 17 and 18 are preformed as at 21 to frictionallyreceive a cap or button 22.

As shown in FIG. 5, the stem 17 of the switch key 13 has formed thereinan aperture 23, while the stem 18 of the switch key 14 is provided onone side wall thereof with a cam surface 24. The opening 19 formed inthe top wall 20 of the body enclosure 12 of the switch key 14 isprovided with an enlargement 25 through which the cam surface 24 may bemoved when the stem 18 is depressed as hereinafter described.

Also provided on the top wall 20 of the body enclosure 12 of the keyswitch 14 is a circular stud 26 which extends vertically therefrom in aspaced parallel relation to the stem 18. This stud provides an enlargedbase flange 27 and a reduced free end 28, such that a shoulder 29 isprovided for a purpose hereinafter made apparent.

The lock-in mechanism of this invention includes a lever 30 which isformed from a single blank of metal stamping in such a manner as toprovide an elongated body 31, one edge of which is notched as at 32. Theedge opposite the notch 32 has a portion removed as at 33, so as toprovide a spring finger 34 which is connected to the body 31 by a lip 35that is bent out of the normal plane of the body 31 so as to dispose thespring finger 34 in a longitudinal plane beneath the normal plane of Allthe body 31. The spring finger 34 is biased in a direction so as to beslightly disposed beneath the body 31 for a purpose hereinafterdescribed.

The lever 30 also provides a locking pin 36 which is of a size to bereadily projected into the aperture 23 formed in the stem 17 of the key13. The body 31 of the lever 30 has formed therein a circular opening 37which is of a size to receive the circular stud 26 and yet rest upon thebase flange 27 provided thereby, as clearly shown in FIG. 7.

A retaining washer 38 is adapted to be projected upon the reduced freeend 28 of the stud 26 and rests agairst the shoulder 29 providedthereby, with the free end 28 of the stud 26 swaged over the washer 38so as to retain the lever 30 on the stud 26 for free pivotal movement.

When the lever 30 is mounted upon the stud 26 provided by the key switch14, the spring finger 34 will engage one edge of the peripheral flange15 thereof and by reason of its canted relation to the body 31, willbias the lever 30 in a counterclockwise direction as shown in FIG. 2. Insuch position, the lever 30 tends to pivot in a clockwise direction asshown in FIG. 2, about the stud 26. However, such movement is resistedby the fact that the pin 36 is in contact with a portion of the stem 17of the associated key switch 13 adjacent to but not in alignment withthe aperture 23 formed therein.

It should be noted that the keyboard openings 11 are so related, one toanother, that the key switches 13 and 14 will be in a specific offsetrelation one to another, as shown.

When the stem 17 of the key switch 13 is manually depressed, suchmovement will cause the aperture 23 fomied therein to be moved intoalignment with the locking pin 36, and the continuing self-biasingaction of the lever 30 will force the pin 36 into the aperture 23 andlock the stem 17 in a depressed condition as shown in FIG. 3.

The key switch 13 will remain in its depressed locked condition untilthe stem 18 of the key switch 14 is manually depressed. By this action,the cam surface 24 will bear against the notched edge 32 of the body 31of the lever 30 and physically pivot the lever 30in a clockwisedirection about the stud 26 so as to withdraw the locking pin 36 fromthe aperture 33 formed in the stem 17 of the key switch 13, permittingthe same to be mechanically self-restored to its original position, suchas shown in FIG. 4.

In some installations of the locking mechanism it is desirable to havemore than one key switch capable of efiecting release of the lockinglever 30 from the stem 17 of the key switch 13. Such an arrangement isshown in FIG. 1, where another key switch 39 having the sameconstruction and components as the key switch 14, is carried in one ofthe openings 1 1 formed in the keyboard 10. The locking lever 42associated with the key switch 39 does not provide a locking pin 36, butis connected to the locking lever 30 of the key switch 14 by aconnecting means 40, such as an extremely thin but durable rod or wirestrand. Thus, when the stem 41 of the key switch 39 is depressed, itscam surface will pivot its associated locking lever 42 in a clockwisedirection, which through the connecting means 40 will also effectpivotal movement of the locking lever 30 of the key switch 14 in a likedirection. Thus, if the locking lever 30 had been self-biased into alocking position with respect to the stem 17 of the key switch 13, suchlocking position would be changed by the actuation of either of the keyswitches 14 or 39.

I have provided a simple locking lever which contains as an integralpart thereof a canted spring finger which biases the locking lever intooperative position, or which maintains the locking lever in a readyposition with respect to an associated switch for automatic pivotalmovement when desired.

While I have illustrated and described the preferred form ofconstruction for carrying my invention into effect, this is capable ofvariation and modification without departing from the spirit of theinvention. 1, therefore, do not wish to be limited to the precisedetails of construction set forth, but desire to avail myself of suchvariations and modifications as come within the scope of the appendedclaims.

improvement comprises a. an apertured stem provided by the first key,

b. latch means carried by the second key and extending laterallytherefrom so as to have a free end positioned in close proximity to saidstern of the first key,

c, means for pivotally supporting said latch means on the second keywhereby it may be pivoted through a plane extending transversely to thenormal plane of said stem of the first key,

d. means on said latch means for biasing the free end thereof in onedirection about said pivotal connection to the second key and intocontact with the stem of the first key,

e. means provided by the free end of said latch means adjacent said stemof the first key and normally out of alignment with said aperture formedtherein and adapted to be projected therein when the first key is movedinto an operative position for latching the same,

f. and means on the stem of the second key for pivoting said latch meansin an opposite direction about said pivotal connection to the second keyand against said biasing means so as to withdraw said projecting meansout of said aperture in said stem of the first key to permit it toreturn to its inoperative position.

2. A mechanical lock-in for a selected key of a keyboard as defined byclaim I, wherein said means on said latch means for biasing the free endthereof in one direction comprises a spring finger adapted to bearagainst the second key when said latch means is pivotally mountedthereto, so as to bias said latch means in one direction relativethereto.

3. A mechanical lock-in for a selected key of a keyboard as defined byclaim 1, wherein said latch means comprises an elongated substantiallyflat lever of a length to extend between the sterrs of the first andsecond keys and which is pivotally connected to the second key andprovides a free end adjacent to the stem of the first key.

4. A mechanical lock-in for a selected key of a keyboard as defined byclaim 3, wherein said means for biasing said lever in one directionabout its connection to the second key comprises a spring finger bentout of the substantially flat plane of said lever and adapted to bearagainst the second key so as to bias said lever in one direction and inthe direction of the stem of the first key.

5. A mechanical lock-in for a selected key of a keyboard as defined byclaim 1, wherein said means provided by the free end of said latch meanswhich is normally out of alignment with said aperture formed in saidstem of the first key, is a locking pin extending transversely of thenormal plane of said latch means and having contact with said stem ofthe first key as said latch means is biased in one direction about itspivotal connection to the second key, with said locking pin adapted tobe forcibly projected by said biasing means into said aperture of saidstem of the first key when the first key is moved into an operativeposition.

6. A mechanical lock-in for a selected key of a keyboard as defined byclaim 5, wherein said means for biasing said latch means in onedirection about its pivotal connection to the second key includes aspring finger provided by said latch means and adapted to bear againstthe second key so as to bias said latch means and said locking pin inone direction into contact with said stem provided by the first key andto further bias said locking pin into said aperture formed in said stemof the first key when the first key is moved into an operative position.

1. A mechanical lock-in for a selected key of a keyboard including firstand second juxtaposed keys having stemlike supporting members, the firstkey being the selected key to be locked in and the second key effectingits release, wherein the improvement comprises a. an apertured stemprovided by the first key, b. latch means carried by the second key andextending laterally therefrom so as to have a free end positioned inclose proximity to said stem of the first key, c. means for pivotallysupporting said latch means on the second key whereby it may be pivotedthrough a plane extending transversely to the normal plane of said stemof the first key, d. means on said latch means for biasing the free endthereof in one direction about said pivotal connection to the second keyand into contact with the stem of the first key, e. means provided bythe free end of said latch means adjacent said stem of the first key andnormally out of alignment with said aperture formed therein and adaptedto be projected therein when the first key is moved into an operativeposition for latching the same, f. and means on the stem of the secondkey for pivoting said latch means in an opposite direction about saidpivotal connection to the second key and against said biasing means soas to withdraw said projecting means out of said aperture in said stemof the first key to permit it to return to its inoperative position. 2.A mechanical lock-in for a selected key of a keyboard as defined byclaim 1, wherein said means on said latch means for biasing the free endthereof in one direction comprises a spring finger adapted to bearagainst the second key when said latch means is pivotally mountedthereto, so as to bias said latch means in one direction relativethereto.
 3. A mechanical lock-in for a selected key of a keyboard asdefined by claim 1, wherein said latch means comprises an elongatedsubstantially flat lever of a length to extend between the stems of thefirst and second keys and which is pivotally connected to the second keyand provides a free end adjacent to the stem of the first key.
 4. Amechanical lock-in for a selected key of a keyboard as defined by claim3, wherein said means for biasing said lever in one direction about itsconnection to the second key comprises a spring finger bent out of thesubstantially flat plane of said lever and adapted to bear against thesecond key so as to bias said lever in one direction and in thedirection of the stem of the first key.
 5. A mechanical lock-in for aselected key of a keyboard as defined by claim 1, wherein said meansprovided by the free end of said latch means which is normally out ofalignment with said aperture formed in said stem of the first key, is alocking pin extending transversely of the normal plane of said latchmeans and having contact with said stem of the first key as said latchmeans is biased in one direction about its pivotal connection to thesecond key, with said locking pin adapted to be forcibly projected bysaid biasing means into said aperture of said stem of the first key whenthe firSt key is moved into an operative position.
 6. A mechanicallock-in for a selected key of a keyboard as defined by claim 5, whereinsaid means for biasing said latch means in one direction about itspivotal connection to the second key includes a spring finger providedby said latch means and adapted to bear against the second key so as tobias said latch means and said locking pin in one direction into contactwith said stem provided by the first key and to further bias saidlocking pin into said aperture formed in said stem of the first key whenthe first key is moved into an operative position.